package com.example.manager;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DatabaseHelper extends SQLiteOpenHelper {
	
	private static String DB_PATH = "/data/data/etc.com.android/databases/";
    private static String DB_NAME = "smartbus.sqlite";
    private SQLiteDatabase myDataBase; 
    private Context myContext = null;
          
	public DatabaseHelper(Context context, String name, CursorFactory factory,
			int version) {
		super(context, name, factory, version);
		
	}

	public DatabaseHelper(Context context){
		super(context, DB_NAME, null, 1);
		myContext = context;
	}
   
    public void createDataBase() throws IOException{
    	 
    	boolean dbExist = checkDataBase();
 
    	if(dbExist){
    		//myContext.deleteDatabase(DB_PATH+DB_NAME);
    		//myContext.deleteFile(DB_PATH+DB_NAME);
    	}else{
 
    		//By calling this method and empty database will be created into the default system path
               //of your application so we are gonna be able to overwrite that database with our database.
        	this.getReadableDatabase();
 
        	try {
 
    			copyDataBase();
 
    		} catch (IOException e) {
 
        		throw new Error("Error copying database");
 
        	}
    	}
 
    }
    
    private boolean checkDataBase(){
    	 
    	SQLiteDatabase checkDB = null;
 
    	try{
    		String myPath = DB_PATH + DB_NAME;
    		checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
 
    	}catch(SQLiteException e){
 
    		//database does't exist yet.
 
    	}
 
    	if(checkDB != null){
 
    		checkDB.close();
 
    	}
 
    	return checkDB != null ? true : false;
    }
 
    private void copyDataBase() throws IOException{
    	 
    	//Open your local db as the input stream
    	try{
    		InputStream myInput = myContext.getAssets().open(DB_NAME);
 
    		// Path to the just created empty db
    		String outFileName = DB_PATH + DB_NAME;
 
    		//Open the empty db as the output stream
    		OutputStream myOutput = new FileOutputStream(outFileName);
 
    		//transfer bytes from the inputfile to the outputfile
    		byte[] buffer = new byte[1024];
    		int length;
    		while ((length = myInput.read(buffer))>0){
    			myOutput.write(buffer, 0, length);
    		}
    	
    		//Close the streams
    		myOutput.flush();
    		myOutput.close();
    		myInput.close();
    	}
    	catch(Exception e){
    		Log.e("Error in copying database file",e.getMessage());
    	}
 
    }
   
    public void openDataBase() throws SQLException{
    	 
    	//Open the database
        String myPath = DB_PATH + DB_NAME;
    	myDataBase = SQLiteDatabase.openDatabase(myPath, null,
                SQLiteDatabase.CREATE_IF_NECESSARY);
    	try{
			myDataBase = getWritableDatabase();
		}
		catch(SQLiteException e){
			Log.d("DB Error", e.getMessage());
		}
    }
 
    @Override
	public synchronized void close() {
 
    	    if(myDataBase != null)
    		    myDataBase.close();
 
    	    super.close();
 
	}
    
   
	@Override
	public void onCreate(SQLiteDatabase arg0) {
		// TODO Auto-generated method stub

	}

	@Override
	public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {
		// TODO Auto-generated method stub

	}

	public Cursor ExecuteQuery(String tableName, String[] columns){
		try{
			return myDataBase.query(true, tableName,columns, null, null, null, null,null , null);
		}catch(Exception e){
			Log.e("Database Error", e.getMessage());
			return null;
		}
	}
	
	public Cursor ExecuteQuery(String tableName,String[] columns, String where){
		try{
			return myDataBase.query(tableName, columns, where, null, null, null, null);
		}catch(Exception e){
			Log.e("Database Error", e.getMessage());
			return null;
		}
		
	}
	
	public Cursor ExecuteQuery(String tableName,String[] columns,String where, String sort){
		try{
			return myDataBase.query(true, tableName,columns, where, null, null, null,sort, null);
		}catch(Exception e){
			Log.e("Database Error", e.getMessage());
			return null;
		}
	}
	
	public Cursor ExecuteQueryWithSort(String tableName,String[] columns, String sort){
		try{
			return myDataBase.query(true, tableName,columns, null, null, null, null,sort, null);
		}catch(Exception e){
			Log.e("Database Error", e.getMessage());
			return null;
		}
	}
	
	public Cursor ExecuteRawQuery(String query,String[] columns){
		try{
			return myDataBase.rawQuery(query,columns);
		}catch(Exception e){
			Log.e("Database Error", e.getMessage());
			return null;
		}
	}
}
